For displays utilized in a graphic design field or the like, a display performance of reproducing uniform colors over the entire screen is required.
Patent Document 1 discloses a related technique for correction of luminance unevenness or color unevenness.
In an image display apparatus disclosed in Patent Document 1, an input video signal is displayed on a display panel. This image display apparatus inputs a white (color) signal of approximately 100% white level onto the display panel which displays this signal. The displayed white screen is imaged by using an imaging device, and the image display apparatus has a computation device of computing a reciprocal of a luminance signal and/or a color signal obtained by the imaging. The image display apparatus also has (i) a memory utilized to store the reciprocal computed by the computation device as correction data, and (ii) a correction device that corrects luminance unevenness and/or color unevenness generated on the display panel by multiplying the correction data stored in the memory by the input video signal.
Accordingly, in the image display apparatus disclosed in Patent Document 1, a white signal, for example, 100 IRE (100% white level) is displayed on a liquid crystal panel, and the displayed white screen is imaged by using the imaging device so as to detect luminance unevenness or color unevenness for the white screen, which is generated on the display screen of the liquid crystal panel, as a level difference in the output video signal for the luminance or color. Then, a reciprocal of the video signal having the level difference detected by using the imaging device is multiplied by the video signal input into the liquid crystal display apparatus, so as to perform the correction to obtain uniform luminance or color.